1. Field of the Invention
The present invention relates to a perpendicular magnetic write head provided with a magnetic pole and a side shield layer, and a magnetic recording device incorporating the head.
2. Description of the Related Art
Due to the recent increase of the areal recording density of a magnetic recording medium (hereinafter, referred to as “recording medium”) typified by a hard disk, there is a demand for the better performance capabilities of a magnetic write head. In order to meet such a demand, as an alternative to the longitudinal magnetic recording mode that has been the recording mode for the magnetic write head, the perpendicular magnetic recording mode is now receiving attention. With the longitudinal magnetic recording mode, the direction of a signal magnetic field is set to be in the in-plane direction of a recording medium, and with the perpendicular magnetic recording mode, the direction thereof is set to intersect with the plane thereof. This is due to advantages of a higher linear recording density, and less susceptibility of any recording medium completed with recording to thermal fluctuations.
A magnetic write head of such a perpendicular magnetic recording mode (hereinafter, referred to as “perpendicular magnetic write head”) is provided not only with a thin-film coil for use to generate magnetic fluxes but also with a main magnetic-pole layer for use to direct, to a recording medium, the magnetic fluxes generated by the thin-film coil, for example. This main magnetic-pole layer includes a tip end portion (magnetic pole) of a very narrow width for generation of a magnetic field for recording use (recording magnetic field).
As to the configuration of such a perpendicular magnetic write head, providing a side shield layer thereto has been under study to respond to the increasing recording density without increasing the size of the recording magnetic field. The side shield layer is to be provided via a gap on both sides of the magnetic pole in the width direction of a recording track (examples for reference include Japanese Unexamined Patent Publication Nos. 2004-326990, 2004-022004, and 2005-310363).
In such circumstances, the areal recording density of the recording medium is increasing all the more, and thus recently, the demand is increasing for the more appropriate configuration of the perpendicular magnetic write head. With the previous perpendicular magnetic write head provided with the side shield layers, however, ensuring the recording magnetic field to be adequate in intensity is in a relationship of “trade-off” with not increasing the size thereof, and such attempts are difficult to be achieved at the same time. There is thus still a room for improvement in terms of recording capabilities.
As such, improving the recording capabilities is very much expected through achievement of such attempts at the same time of ensuring the recording magnetic field to be adequate in intensity while not increasing the size thereof.